£320 for backbox + 1 res, £350 both res and backbox

M140i/M240i/M340i/M440i/M640i OEM exhaust mod

I've modded lots of these with great results, a deeper, aggressive sound with clearer more defined crackles.

the process involves me removing the exhaust from the car and opening the silencers from above, inside each is a series of chambers and pipework, I use stainless parts and welding to internally alter the airflow, once put back together and back on the car no evidence of my work can be seen.

this also leaves the valve functional so you still have a loud/quiet option, meaning no drone when cruising.

here is a diagram of the '40i' exhaust.

This modification is issue free, never had any warranty issues, MOT, Emissions all unaffected, I offer a guarantee of all my work for the lifetime of your ownership of the car.

please check out the videos, the mod is £320 for 1 res and backbox £350 for both resonators and backbox, I can be contacted on 07941 966010 for any further questions.

both resonators and backbox below

there is also the opf/ppf/gpf model which is july 2018 build date onwards, this exhaust does not have the resonator nearest the downpipe but instead has a new petrol particulate filter.

the filter can not be removed without mapping, which i can do if required via Bootmod3.

the standard mod without mapping is the larger resonator and backbox which makes it £330. no issues will be caused with the filter, bmw changed the mapping on the filter model also, so they are very occasional rather than whenever you let off, a deeper much better exhaust note is still achieved from modification though. a video off a filter model below.